Hey guys,

I'm new to the turbo scene. I finished installing my greddy turbo kit on AP1 two weeks ago and I'm currently running on the base map from greddy.

The car has been driving smooth until yesterday. Yesterday I drove to work for the first time. The morning drive was good and smooth I didn't go into boost or anything. A/F were in the 14.7s

After work, I think the temperature outside was in the high 80s, I started the car and the revs went up and down. A/F gauge had no reading I guess it was higher than 17s? it eventually settled down to the 14s when it was completely warmed up.

I tried driving the car home, but when I stop on a traffic light my engine would stall. A/F readings were around 10s/11s. I had to constantly rev it to prevent stalling and to get to 13s/14s and sometimes 15s-17s on my A/F.

Has anyone experienced this before on a greddy kit? Does it have anything to do with the temperature outside. I think yesterday was probably the hottest day I drove it ever since i finished installing the turbo.

 

Do you have any other aftermarket parts installed? Other than the temperature, what changed? Check to see if an injector connection is loose?

 

I have a Berk HFC and Tanabe Exhaust

 

I've read somewhere that you can cause overboost conditions with a higher flowing exhaust, do you have a boost gauge? Can you check the boost level? Maybe the wastegate is stuck closed? I don't understand why it would happen all of a sudden though. Is this behavior consistent? Or did it just start happening all the time?

 

I have a boost gauge. I think its reading correctly. I haven't pushed the car that hard yet because I rebuilt the engine not too long ago it has 1000+ miles on it. The highest boost I probably went to is 2 psi.

It just started happening a few days ago. I just cleaned the IACV and its running a little bit better. Now when I'm upshifting, it either goes completely lean or it goes to the 10s AFR. Is this normal?

Next, I'm planning to jack up the car and check anything that's loose..

 

Try not to narrow ur "solutions" or over think it. I had a discrepancy going on where my OEM o2 that was 18" from turbine outlet on beginning of downpipe read correct, but my standalone wideband was stupid lean @idle located at test pipe. At cruise n wot they would sync up but idle it would just creep lean. Finally found that my downpipe vband to test pipe connection was cocked leaving a leak inbetween. As the back pressure equalized at idle in exhaust the leak would lean WBo2, but during cruise n wot the leak became a restriction. Allowing afrs to be the same in both areas of exhaust showing similar readings. Now b4 getting to that point my OEM was a lil lean at idle to but because of a bad dead times set, but it was no where near the WB because of this other problem ^^

I had gone from probably ten different theory's as to why this was happening. Pretty much all of them were replacing sensors($$) or tracking a bad ground. Finally threw it on a lift and found that. I paid 5$ for the lift. That's when I told myself to not over think stuff... Resilience training and decision making process is invaluable in these situations. Don't get frustrated or impatient, sometimes you just have to check your work a lil. Maintenance and a habitual open hood inspection also goes without saying. "Stay dirty my friend" dos aquis

During shifts I usually see a rich spike at first or (momentarily) U can probably read AEMs FPR instruction on there replaceable orifices to gain understanding why this happens. Furthermore I think their is some contributing factors like when you go from wot to a full shut throttle plate all the suction or "vacuum" can pull some extra fuel from injectors. Also the ECU and o2 needs time to react to those two full spectrums of the fuel map. So injectors are on full blast because it's reading xyz @WOT, in a instant throttle plate shuts immediately causing a lot less air. Your o2 reads that as rich for that instance of air (remember it actually takes time to move, combust, travel to o2, ALL while the ECU is trying to navigate the new fuel mixture.

You'll figure it out lol. Just takes time...

 

Do you think that the position of the WB O2 sensor matters? I bought a used downpipe and it came with a welded bung for the WB sensor is almost parallel to the ground and its also 24 inches away from the turbo.. I'm thinking of removing the downpipe/cat and have another bung welded about 36 inches away from the turbo and at an angle based on the AEM installation instructions.. I'll see if that will fix my problem..

I was reading in the evo forums on another site.. and some guy is having the same issue as me and some guy told him this:

"When you close the throttle, the airflow INTO the engine is cut off and the intake manifold pressure goes very low (high vacuum). So all the remaining fuel droplets on the intake walls of the manifold and ports will immediately boil (evaporate) and get sucked into the engine. So for that moment, until all the fuel residue is removed, the exhaust will be very rich. How rich? Depends. Then after all the fuel residue has been removed, and the throttle is still closed, the exhaust will be full lean as there is no fuel being injected during deceleration for most RPM ranges while it is still getting some air. Note that in the X when you get off the throttle pedal, the throttle plate is NOT completely closed for a couple seconds so there is some additional air entering the engine to help with burning all that extra fuel that just boiled off. " (evoxforums). Work Cited.. LOL. I guess that makes sense.